1. Field of the Invention
This invention relates generally to surgical instruments, and more particularly, to a surgical instrument for crimping a sleeve to a secured suture that is more easily manufactured than instruments heretofore known.
2. Background Art
Malleable sleeves such as the sleeves sold under the trademark Titanium Knot by LSI Solutions are a significant improvement over hand or instrument-tied knots in laparoscopic surgical procedures. The sleeves, which are made of a malleable material compatible with prolonged exposure to body tissue are slid over two or more strands of suture and deformed or crimped to secure the strands of suture.
An example of an instrument for crimping a sleeve of the type described is shown in U.S. Pat. No. 6,368,334, entitled “VASCULAR HOLE CLOSURE.” The crimper shown in the patent deforms the sleeve between two relatively moveable jaws when a lever on the instrument is squeezed toward the handle. The instrument described performs its function satisfactorily but is demanding to manufacture.
It is desirable to impart just enough, but not too much, pressure on the sleeve to deform it to a desired extent. If the sleeve is insufficiently deformed, the sutures may slip, and if the sleeve is deformed too much, it may be weakened and not secure the sutures for as long as is intended.
Known crimping instruments rely on the accurate manufacture of the relatively movable parts to establish the extent to which the sleeve will be crimped. Also, in known crimping instruments, the distance a pusher rod moves to force the jaws on which the hammer and anvil are disposed together affects the amount of crimp. This creates the possibility that, if the tolerances are not exact, or the surgeon does not completely squeeze the actuating handle to the lever, the sleeve may be incompletely crimped and may slip, or may be over crimped and weakened.
While a large number of crimpers in accordance with the prior art have been made, the cost of maintaining the manufacturing tolerances necessary to insure that these crimpers perform adequately, has been high. There is a need for an improved crimper that continues to perform as well as the existing crimpers, but which can be made without the need for maintaining the manufacturing tolerances for the parts and assembly at the very high levels required by the existing designs.
It is an object of this invention to provide a crimper for surgical suturing operations that overcomes the disadvantages of crimpers heretofore known.
It is another object of this invention to provide a crimper that is easy to manufacture, and at the same time, retains or improves on the crimping quality of crimpers heretofore known.